We've had both, just recently we gave the mandarin back to the LFS
because of combining our tanks and knew if we kept the mandarin with the scooter that either the mandarin would die of starvation or the scooter would chase her to death. We had our mandarin in a 40 gallon all by itself no other fish along with fuge, it wouldn't eat frozen food either.
Our scooter on the other hand we have had for a year, will eat frozen brine, mysis, zooplankton and believe it or not even the mush we make that has fallen down onto the sand big pieces too! It's a great fish to watch, they seem to glide in the water and will occasionally show off, hope you don't mind me posting a pic of ours.
Good luck in what ever you decide